What Chicago Referencing Actually Is
Chicago is the referencing style of the University of Chicago Press, and the default in history, art history, theology, and much of the humanities. If your module handbook says “use Chicago,” it means one thing above all: footnotes.
The catch: Chicago is really two systems wearing one name, and students lose marks by mixing them up. This guide covers both, with worked examples you can copy the shape of.
The Two Systems: Notes-and-Bibliography vs Author-Date
Notes-and-bibliography (NB) is the classic Chicago system and the one most humanities departments use: numbered footnotes at the bottom of each page, plus a full bibliography at the end. A first footnote gives complete publication details; later notes for the same source are shortened.
Author-date works like APA or Harvard: brief citations in brackets in the text — (Thompson, 2021, 45) — plus a reference list at the end. It is common in the sciences and social sciences that use Chicago.
If your brief says “Chicago” without specifying, and you are in history or a humanities subject, assume notes-and-bibliography. Never run both systems in one essay — that is the single most common Chicago error, and markers spot it instantly.
The version in force is the 17th edition of the Chicago Manual of Style (2017). If your department has its own Chicago-based house guide, that guide wins where it disagrees with the manual.
Notes-and-Bibliography: The Footnote Rules
Footnotes are numbered in the order sources appear, starting at 1 on each page or continuing through the chapter — follow your department’s preference. The footnote marker is a small superscript number placed after the punctuation at the end of the clause or sentence it refers to, like this.1
A first footnote for a book gives the full details:
1. Mary Beard, SPQR: A History of Ancient Rome (London: Profile Books, 2015), 142.
The anatomy: author (first name first), book title in italics, publication details in brackets, then the page number you are citing. Note the commas, and the full stop at the very end.
A journal article’s first footnote looks like this:
2. David Edgerton, “The Contradictions of Techno-Nationalism and Techno-Globalism: A Historical Perspective,” New Global Studies 2, no. 1 (2008): 12.
Article titles go in quotation marks; the journal name is italicised; volume and issue follow, then the year in brackets and the page cited.
A website’s first footnote:
3. “World’s Oldest Stone Tools Found in Kenya,” Nature, April 14, 2015, https://www.nature.com/news/world-s-oldest-stone-tools-found-in-kenya-1.17306.
Include the access date for web sources if your department asks for it — many do, since web pages change. When in doubt, include it: “accessed October 10, 2026.”
Shortened Notes: What the Second Citation Looks Like
Later references to a cited source shrink to a short form: surname, shortened title, page:
4. Beard, SPQR, 210.
If you cite the same source twice in a row, Chicago lets you use “Ibid.” (short for ibidem, “in the same place”) instead of repeating the short form:
5. Ibid., 212.
“Ibid.” alone means the same source and the same page as the previous note. “Ibid., 212” means the same source, a different page. But the moment any other source intervenes, go back to the shortened form, not Ibid. Note that some departments now prefer shortened notes over Ibid. — check your handbook.
The Bibliography: How It Differs From the Notes
The bibliography sits at the end of your essay, lists every source you cited, and is alphabetical by author’s surname. Its entries look similar to first footnotes — but not identical, and the differences are exactly what markers check: the author’s name is inverted (“Beard, Mary”), entries use full stops between the main parts instead of commas and brackets, there is no page number for the specific passage cited, and entries use a hanging indent.
The same book in the bibliography:
Beard, Mary. SPQR: A History of Ancient Rome. London: Profile Books, 2015.
The same journal article:
Edgerton, David. “The Contradictions of Techno-Nationalism and Techno-Globalism: A Historical Perspective.” New Global Studies 2, no. 1 (2008): 1–27.
Note the article entry gives the full page range (1–27), while the footnote gave only the page cited (12). That is the rule: footnotes point at the exact passage; bibliography entries describe the whole source.
Book chapters, edited volumes, and websites follow the same logic — full details, surname first, hanging indent. For a chapter: author, chapter title in quotes, then “in” the book title in italics, the editor, publication details, and the chapter’s page range.
Author-Date: The Other Chicago System
If your department uses author-date, the in-text citation is brief and parenthetical:
(Beard 2015, 142)
No comma between author and year, and the page number follows after a comma. If the author’s name is already in your sentence, only the year and page go in brackets: “Beard (2015, 142) argues…”
The reference list entry mirrors the bibliography form with one twist: the year moves up, directly after the author’s name:
Beard, Mary. 2015. SPQR: A History of Ancient Rome. London: Profile Books.
Everything else — italics, hanging indent, alphabetical order — works the same as the bibliography.
Worked Examples: The Sources You’ll Actually Cite
Book, single author (footnote then bibliography):
1. Kate Raworth, Doughnut Economics: Seven Ways to Think Like a 21st-Century Economist (London: Random House Business, 2017), 88.
Raworth, Kate. Doughnut Economics: Seven Ways to Think Like a 21st-Century Economist. London: Random House Business, 2017.
Journal article:
2. Sven Beckert, “Emancipation and Empire: Reconstructing the Worldwide Web of Cotton Production in the Age of the American Civil War,” American Historical Review 109, no. 5 (2004): 1405.
Beckert, Sven. “Emancipation and Empire: Reconstructing the Worldwide Web of Cotton Production in the Age of the American Civil War.” American Historical Review 109, no. 5 (2004): 1405–38.
Book chapter in an edited volume:
3. Emma Griffin, “The Emotions of the Industrial Revolution,” in The Palgrave Handbook of the History of Childhood, ed. Paula Fass (Basingstoke: Palgrave Macmillan, 2017), 215.
Griffin, Emma. “The Emotions of the Industrial Revolution.” In The Palgrave Handbook of the History of Childhood, edited by Paula Fass, 207–22. Basingstoke: Palgrave Macmillan, 2017.
Website:
4. “The British Museum: History,” British Museum, accessed October 10, 2026, https://www.britishmuseum.org/about-us/british-museum-story/history.
British Museum. “The British Museum: History.” Accessed October 10, 2026. https://www.britishmuseum.org/about-us/british-museum-story/history.
The pattern is consistent once you see it: footnote = first name first, commas, page cited; bibliography = surname first, full stops, full page range.
Mistakes That Cost Marks
Mixing the two systems. Footnotes and author-date citations in the same essay is the classic Chicago error. Pick one and commit.
Footnote numbers before punctuation. The superscript goes after the full stop or comma, not before it. “…as Beard argues.1” is right; “…as Beard argues1.” is wrong.
Copying footnote format into the bibliography. The inverted name, the full stops, and the hanging indent are what make a bibliography entry different. A bibliography that is just your footnotes pasted in order will be marked down.
Forgetting the bibliography entirely. Footnotes alone are not enough in the notes-and-bibliography system. The bibliography is required, even though the footnotes already carry the details.
“Ibid.” after a different source. Ibid. only ever refers to the immediately preceding note. If anything else sits between, use the shortened form.
No access dates on web sources. Web pages move and change. Your department’s guide may require access dates; include them unless told otherwise.
Chicago vs Harvard, APA, and MLA at a Glance
If you have used other styles, this comparison helps you reset:
- Chicago (NB): footnotes + bibliography. Page-focused and source-rich; the humanities standard. Compare our Harvard referencing guide and APA referencing guide for the author-date alternatives.
- Chicago (author-date): (Author Year, Page) + reference list. Same logic as Harvard, different punctuation — no comma between author and year.
- MLA: (Author Page) + Works Cited. Page-focused like Chicago NB, but with no year and no footnotes — see our MLA referencing guide for the contrast.
A Final Checklist Before You Submit
- One Chicago system used throughout — never both
- Footnote markers placed after punctuation, numbered in order
- First footnote for each source gives full details; later notes are shortened
- “Ibid.” used only for the immediately preceding note
- Bibliography is alphabetical, surname first, with hanging indents
- Bibliography entries give full page ranges; footnotes give pages cited
- Web sources include access dates (unless your guide says otherwise)
- Every footnote source appears in the bibliography, and vice versa
For the authoritative rules, the Chicago Manual of Style’s free citation guide covers both systems with official examples, and Purdue OWL’s Chicago style guide is the clearest free walkthrough of the 17th edition.
Need a Hand With Your Referencing?
Chicago is the most detail-heavy of the major styles, and it punishes small slips — a misplaced full stop, a footnote copied into the bibliography, an Ibid. pointing at the wrong note. If your draft is done but the footnotes are a mess, The Pen Master can sort it. Our subject-matched academic writers format references to any style — Chicago, Harvard, APA, MLA — as part of full assignments or standalone proofreading and editing. Message us on WhatsApp at +49 1521 3962850 for a quick quote, or send your brief through the contact form on thepenmaster.com and we will take it from there.